The invention relates to a medical instrument for suction and irrigation, having an elongate shaft with one channel serving as suction channel and with another channel serving as irrigation channel.
The invention further relates to a method for producing such a medical instrument.
An instrument of the kind mentioned above is known from the company brochure produced by the German company Karl Storz GmbH & Co. KG, “STORZ Karl Storz-Endoskope”, volume entitled “Laparoskopie”, 3rd edition 2/99, page IS-ACC 5 A.
When performing surgical procedures on the human or animal body, such an instrument is used to irrigate the operating site with fresh irrigation fluid and to suction the irrigation fluid together with blood and tissue residues back out from the operating site. In endoscopic procedures, irrigation also serves to maintain a clear view through an endoscope.
To permit suction and irrigation simultaneously, it is necessary for such an instrument to have a shaft with two channels, specifically a suction channel and an irrigation channel. Since the fresh irrigation fluid should not mix with the suctioned fluid before reaching the operating site, it is also necessary for the irrigation channel to be separated from the suction channel so that irrigation fluid and suctioned fluid do not mix together in the shaft.
The shaft of the instrument known from the abovementioned German company brochure has a first tube for the irrigation channel and a second tube for the suction channel, in which the first tube forming the irrigation channel is pushed as an insert into the second tube forming the suction channel. The suction channel is accordingly formed between the outside face of the first tube forming the irrigation channel and the inside face of the second tube. The shaft of this instrument is thus composed of two tubes which are essentially not connected to one another, and this can lead to a number of disadvantages. On the one hand, individual tubes have less flexural stability, and, on the other hand, they each have to be individually sealed off from the outside by suitable sealing measures, for example O-ring seals, which are subject to wear. The arrangement of an irrigation tube and a suction tube inserted one inside the other also has the disadvantage that, in the suction tube and in the thin irrigation tube, there is no room for insertion of an endoscope, unless the cross section chosen for the whole shaft is of a considerable size, which is undesirable in the field of minimally invasive surgery performed through very small incisions in the body. In addition, the individual tubes have to be assembled before use of the instrument and disassembled before the instrument is cleaned, which makes handling of the instrument difficult.
Moreover, WO 00/48505 discloses an endoscope with an outer shaft in which a shaped shaft divided into chambers is arranged, with one chamber serving as irrigation channel and a separate, further chamber serving as suction channel. In the shaped shaft there is also an optical channel for receiving an optical system and further chambers for receiving a light-transmitting system, for example optical fibers. In this design, although the irrigation channel and the suction channel are integrally connected to one another, a shaped shaft of this kind is relatively complicated to produce since it can only be made in an extrusion process.